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Full text of "The nomenclature and distribution of some Australian and New Caledonian ants of the genus Leptogenys Roger (= Prionogenys Emery, n. syn.) (Hymenoptera: Formicidae: Ponerinae)."

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THE NOMENCLATURE AND DISTRIBUTION OF SOME AUSTRALIAN 

AND NEW CALEDONIAN ANTS OF THE GENUS LEPTOGENYS ROGER 

(= PRIONOGENYS EMERY, N. SYN.) (HYMENOPTERA: FORMICIDAE: PONERINAE) 

Robert W. Taylor 

Australian National Insect Collection, CSIRO Division of Entomology 
G.P.O. Box 1700, Canberra, 2601, Australia 

Summary 

New synonymies include: Leptogenys Roger, 1861 = Prionogenys Emery, 1895 
[with new combinations L. podenzanai (Emery) and L. rouxi (Emery)] ; L. podenzanai 
= Prionogenys podenzanai malandensis Forel; L. conigera (Mayr) = L. conigera mutans 
Forel; L. diminuta (Fr. Smith) = L. diminuta yarrabahna Forel; and L. excisa (Mayr) 
= L. excisa major Forel. The subspecies L. conigera adlerzi Forel, L. conigera centralis 
Wheeler, L. conigera exigua Crawley, L. fallax fortior Forel and L. turneri longensis 
Forel are elevated to species rank. Several species are illustrated. 

Introduction 

This is the first of several papers reviewing subspecific names current for Australian 
ants with the intention either of synonymising them or of raising them to species rank. 
I consider the subspecies category to have no real facility in formal nomenclature, a 
view shared by most ant taxonomists following Wilson and Brown (1953). A new generic- 
level synonym is also proposed. For publication details and type localities of names 
discussed see Taylor and Brown (1985) or Taylor (1987). General distribution is 
summarised using coordinates in the format 17/145 (= 17S. X 145E.), which specify 
the 1- degree grid cells from which records are known. 

The Synonymy of Prionogenys Emery under Leptogenys Roger 

Genus Leptogenys Roger, 1861 

Leptogenys Roger, 1861, Berl ent. Z. 5, p. 41. Type species: Leptogenys falcigera Roger, 
1861 (designated by Bingham, 1903). 

Prionogenys Emery, 1895, Annls Soc. ent. Belg. 39, p. 348. Types species: Prionogenys 
podenzanai Emery, 1895 (by monotypy), N. Syn. 

Three species-group names have been assigned to Prionogenys: podenzanai (type 
locality-Mt Bellenden Ker, Queensland) (Figs 1, 4); rouxi Emery, 1914 (Mt Canala, 
New Caledonia): and podenzanai malandensis Forel, 1915 (Malanda, Queensland). 
Subspecies malandensis is a NEW JUNIOR SYNONYM of L. podenzanai. Comparison of 
syntype-compared podenzanai vouchers in The Australian National Insect Collection 
(ANIC) with a malandensis syntype from the Museum d'Histoire Naturelle, Geneva, 
Switzerland (Forel Collection), and other ANIC specimens, indicates a single monotypic 
species. 

The generic distinction of Prionogenys rests on the aberrant mandibular and ocular 
characters of podenzanai and rouxi, while acknowledging their close affinity to 
Leptogenys. The mandibles are relatively straight, narrow, and exceptionally long, and 
the eyes relatively advanced on the head (see Figs 1, 4, and the figures of Emery 1895, 
1914). Post-cephalic morphology differs between the two species, within limits normal 
for Leptogenys. Both have pectinate tarsal claws, as in Leptogenys. 

A number of lineages in Leptogenys (including several in Australia) have developed 
otherwise unusual, but equally bizarre, mandibular, ocular and clypeal characteristics, 
presumably as adaptations for the seizure of prey (see Figs 1-3). This is a major feature 
of evolution in the genus. The "Prionogenys" species are unusual in their particular 
physiognomy, but not in my opinion exceptional enough to merit generic distinction in 
a radiation so marked by mandibulo-cephalic eccentricity. 



34 GEN. APPL. ENT. VOL. 20, 1988 

The similarities between podenzanai and rouxi are also likely the result of homo 
plasy. Wilson (1958) demonstrated that the post-cephalic morphology of rouxi more 
closely resembles that of the New Caledonian Leptogenys acutangula Emery than that of 
podenzanai, perhaps indicating relationship. He suggested that the "Prionogenys" habitus 
could have evolved convergently in podenzanai and rouxi. This argument is supported by 
the resemblence in post-cephalic structure between podenzanai and the Australian 
Leptogenys mjobergi Forel. Their mesosomal morphology is similar, distinctive among 
regional Leptogenys, and unlike rouxi and acutangula. Furthermore, the mandibles of 
podenzanai and rouxi differ in basic shape and dentition, and could be only superficially 
similar (Wilson, 1958), while the clypeus is distinctive in each. In rouxi it extends fowards 
between the mandibles as an acute triangular process (not unlike that of L. acutangula), 
while in podenzanai it is much shorter, and surmounted by several bristle-like hairs (a 
configuration readily derived from L. mjobergi-Mks ancestry). 

I conclude that podenzanai and rouxi have evolved separately from more 
conservative Leptogenys stock, that their similarities were convergently acquired, and 
that both should be assigned to Leptogenys. The NEW COMBINATIONS Leptogenys 
podenzanai (Emery) and L. rouxi (Emery) are prescribed. 

ANIC holdings show L. rouxi to be widespread on New Caledonia. L. podenzanai 
is a rainforest-inhabiting species, which can be locally common, and usually nests in the 
soil under stones. It is known at localities on the Atherton Tableland from Lake Eacharn 
National Park south to Tully Falls, from Mt Lewis to the north, and from the Bellenden 
Ker Range to the east (Grid cells 16/145, 17/145). All records are from elevations above 
500 metres, the highest at around 1500 m. 

New Synonymy of some Australian Leptogenys Subspecies 

Leptogenys conigera (Mayr), 1876 
= Leptogenys (Lobopelta) conigera mutans Forel, 1900, N. Syn. 

I have compared ANIC voucher specimens with syntypes of conigera in the 
Naturhistorisches Museum, Vienna (Mayr Collection), and with mutans syntypes in the 
Forel Collection. These specimens and others (ANIC) are almost identical, representing 
an apparently monotypic species. L. conigera inhabits dry savanna and open Eucalyptus 
woodland, and is known from the Townsville area and localities on the western slopes 
of the Great Dividing Range from near Mt Carbine and Dimbulah in the north, south 
to St George, almost at the New South Wales border (Grid cells 16/145, 17/145, 18/145, 
19/146, 21/149, 22/148, 22/150, 23/150, 24/150, 25/149, 25/151, 26/150, 28/148). 
Judging from its habitat preferences L. conigera is probably more widespread than 
indicated. 

Leptogenys diminuta (Fr. Smith), 1857 
= Leptogenys (Lobopelta) diminuta yarrabahna Forel, 1915, N. Syn. (Figs 2, 5). 

This variable species ranges from northern India, Sri Lanka and the Phillippines to 
New Guinea, the Solomon Islands and northern Australia, including the "Top End" of 
the Northern Territory and Cape York Peninsula. Wilson (1958) reviewed the synonymy 
of diminuta and summarised sculptural variation in a matrix table which included 
specimens from Kuranda (16/145), collected not far from the yarrabahna type locality. 
Their attributes, as summarised by Wilson, are typical for material from the base of 
Cape York Peninsula area, and relate to the overall pattern of geographical variation in 
L. diminuta. Wilson's treatment justifies this synonymy. The ANIC has syntypes of 
yarrabahna donated from the Forel Collection. 



TAYLOR: THE GENUS LEPTOGENYS 



35 







Scale = 1mm 

Figs 1-6. Facial and lateral views of three Queensland Leptogenys species. (1, 4) L. podenzanai 
(Topaz area, 17/145); (2, 5) L. diminuta (Mossman Gorge, 16/145); (3, 6) L. longemis 
(Lake Eacham National Park, 17/145). [F. Nanninga del. ] 



36 GEN. APPL. ENT. VOL. 20, 1988 

L. diminuta inhabits areas with marginal vegetation near the edges of rainforest, 
along creek beds etc. and is probably distributed across the network of suitable habitats 
associated with gallery forests in the "Top End" and on Cape York Peninsula. It has 
been taken in such places in the Northern Territory (Oolloo Crossing on the upper Daly 
River, and in Kakadu National Park), and west of the Atherton Tableland (e.g. near 
Ravenshoe). Queensland localities include Iron Range, sites along the coastal strip from 
Mossman and the Daintree River south to near Babinda and Tully, and Palm Island. I 
have never encountered diminuta on the Atherton Tableland proper, west of the coastal 
strip. It could be limited there by the severe, often frosty, winter climate. (Grid cells: 
Northern Territory: 12/133, 13/130; Queensland: 12/143, 16/145, 17/145, 17/146, 
18/146). 

Leptogenys excisa (Mayr), 1876 
= Leptogenys (Lobopelta) excisqpFoie\, 1910, N. Syn. 

L. excisa was described from Rockhampton, Queensland, and major from Tweed 
River, New South Wales. The ANIC has syntype-compared paradigms of excisa, and 
two workers (on a single pin) with label data identical to that of the major types. The 
latter lack formal type labels, but have a characteristically folded thin paper label 
handwritten by Forel, which reads "Lobopelta excisa Mayr n.v. major Forel". They 
are presumably part of the original series, if not syntypes. Other ANIC specimens 
show that the characters supposed by Forel to distinguish major have no taxonomic 
significance, and indicate the presence of a single, moderately variable species ranging., 
in suitable rainforest habitats, from Eungella National Park, near Mackay, south through 
the Gladstone district, Tomewin, Burleigh Heads, Tamborine Mountain, and the 
MacPherson Ranges, Queensland, to Mt Warning and Tweed River, New South Wales 
(Grid cells 21/148, 23/150, 24/151, 27/153, 28/153). There is variation in intensity of 
sculpturation, shape of the relatively massive petiolar node (especially of its posterodorsal 
border, which usually bears a bilateral pair of swollen tumosites), and development of a 
comb-like series of grooves and ridges on the posterior margin of the relatively deep and 
complex transverse groove which follows the dorsal part of the constriction dividing the 
tubulate abdominal segment IV. Variability seems to be allometric rather than geograph- 
ical. It is more pronounced between series from southern localities than among northern 
samples, which are collectively more uniform in size and habitus. There is no evident 
justification for dividing this apparently single species. 

Elevation to Species Rank of Some Australian Leptogenys Subspecies 

Leptogenys adlerzi Forel, 1900 [Leptogenys (Lobopelta) conigera adlerzi] . N. Stat. 

The ANIC has three worker syntypes donated from the Forel Collection. This 
species, like the two following, is smaller and more gracile than L. conigera. L. adlerzi 
is an ordinary Leptogenys of "Lobopelta" habitus. It is broadly and probably locally 
sympatric with L. conigera in northeastern coastal Queensland, notably in the Townsville 
(19/146) area. 

Leptogenys centralis Wheeler, 1915 [Leptogenys (Lobopelta) conigera centralist , N. Stat. 

The ANIC has two worker syntypes and a male. This species resembles L. adlerzi 
in size and habitus, but has different and distinctive proportions. All ANIC collections 
are from Central Australia, mostly from near Alice Springs (23/133). The petiolar nodes 
of L. conigera, L. adlerzi and L. centralis are distinctly longer than high in side view 
(by about 1 .3 to 1 .5 times). 



TAYLOR: THE GENUS LEPTOCENYS 37 

Leptogenys exigua Crawley, 1921 [Leptogenys (Lobopeltd) conigera exigua] , N. Stat. 

ANIC material includes topotypical specimens taken by the original collector, 
G. F. Hill, and identified by John Clark (probably part of the original series retained in 
Australia and not seen by Crawley). Other specimens identified by comparison are all 
from the Darwin/Kakadu National Park area (Grid cells 12/130, 12/132). L. exigua is 
similar in size to L. adlerzi and L. centralis, but has a much shorter petiolar node, 
which is almost as high as long in side view. 

Leptogenys fortior Forel, 1900 [Leptogenys (Lobopelta) fallax fortior] , N. Stat. 

The ANIC has a syntype-compared voucher of L. fallax and five worker syntypes 
and two males of L. fortior. The latter averages larger than L. fallax and has a broader 
head (almost as wide as long in front view), slightly longer antennal scapes (which just 
attain the occipital border when extended), a relatively high petiolar node, the anterior 
and posterior faces of which converge apically in side view to a narrowly rounded 
summit, and longer, more dense, pilosity. The head of L. fallax is distinctly longer than 
broad, the scapes fail to reach the occipital border by about half their maximum diameter, 
and the petiolar node in side view is lower, with a broadly rounded summit and almost 
parallel anterior and posterior faces. L. fallax is represented in the ANIC from Lockerbie 
and Bamaga near the tip of Cape York Peninsula, and localities in the Cairns/ Atherton 
Tableland area, south to Bluff (Grid cells 10/142, 16/145, 17/145, 18/145, 23/149). 
L. fortior is represented from Cape Tribulation, Mossman Gorge, Kuranda, and from 
Townsville and Magnetic Island, south to Byfield, near Yeppoon (Grid cells 16/145, 
17/145, 19/146, 23/150, 24/151). 

Leptogenys longensis Forel, 1915 [Leptogenys (Odontopelta) turneri longemis] , N. Stat. 
(Figs 3, 6). 

The ANIC has syntypes of both turneri and longensis. L. tumeri was described 
from Mackay, and has since been taken in the nearby Eungella and Clarke Range areas, 
and in the northern part of the Paluma Range, southwest of Ingham (Grid cells 18/146, 
21/148). L. longensis was described from Malanda on the Atherton Tableland, further 
north. It is well represented in the ANIC and Queensland Museum collections, ranging 
from Cape Tribulation south to Palmerston National Park (near Crawfords Lookout), 
and at higher elevations from Kuranda and the Lake Tinaroo area to Koombooloomba, 
south of Tully Falls (Grid cells 16/145, 17/144). These rainforest-inhabiting species 
carry a distinctive posterodorsal median spine on the petiolar node, which is shorter in 
L. tumeri than in L. longensis. In addition the latter has stronger mesosomal and 
petiolar sculpturation. There is no evidence of intergradation, and the separate status 
of these species seems assured. 

References 

Emery, C. (1895). Descriptions de quelques fourmis nouvelle d'Australie. Annls Soc. ent. Belg. 

39: 345-358. 
Taylor, R. W. (1987). A checklist of the ants of Australia, New Caledonia and New Zealand. 

(Hymenoptera: Formicidae). CSIRO Aust. Div. Entomol. Rep. 41: 1-92. 
Taylor, R. W. and Brown, D. R. (1985). Hymenoptera: Formicoidea. In Zoological Catalogue of 

Australia, Volume 2. Australian Government publishing Service, Canberra. 381 pp. (1-149, 

306-348). 
Wilson, E. O. (1958). Studies on the ant fauna of Melanesia. I. The tribe Leptogenyini. II. The tribes 

Amblyoponini and Platythyreini. Bull. Mus. comp. Zool. Harv. 118: 101-153. 
Wilson, E. O. and Brown, W. L. (1953). The subspecies concept and its taxonomic application. Syst. 

Zool. 2: 97-111.